Merge pull request matplotlib#22611 from greglucas/axesgrid-inset-cbar

FIX: Colorbars check for subplotspec attribute before using

Author: QuLogic

lib/matplotlib/colorbar.py

@@ -263,12 +263,10 @@ def get_subplotspec(self):
         # make tight_layout happy..
         ss = getattr(self._cbar.ax, 'get_subplotspec', None)
         if ss is None:
-            if self._orig_locator is None:
+            if not hasattr(self._orig_locator, "get_subplotspec"):
                 return None
-            ss = self._orig_locator.get_subplotspec()
-        else:
-            ss = ss()
-        return ss
+            ss = self._orig_locator.get_subplotspec
+        return ss()
 
 
 @docstring.Substitution(_colormap_kw_doc)

lib/mpl_toolkits/tests/test_axes_grid1.py

@@ -100,6 +100,18 @@ def test_axesgrid_colorbar_log_smoketest():
     grid.cbar_axes[0].colorbar(im)
 
 
+def test_inset_colorbar_tight_layout_smoketest():
+    fig, ax = plt.subplots(1, 1)
+    pts = ax.scatter([0, 1], [0, 1], c=[1, 5])
+
+    cax = inset_axes(ax, width="3%", height="70%")
+    plt.colorbar(pts, cax=cax)
+
+    with pytest.warns(UserWarning, match="This figure includes Axes"):
+        # Will warn, but not raise an error
+        plt.tight_layout()
+
+
 @image_comparison(['inset_locator.png'], style='default', remove_text=True)
 def test_inset_locator():
     fig, ax = plt.subplots(figsize=[5, 4])